Cooking apparatus



July 1, 1941. B MES 2,247,626

COOKING APPARATUS "Filed Nov. 9,. 1938 5 Sheets-Sheet l July 1, 1941.

B. AME s COOKING APPARATUS 'Filed Nov. 9, 193a 5 Sheets-Sheet 2 July 1, 1941. 3 AMES. 2,247,626

COOKING APPARATUS Filed'Nov. 9, 1958 5 Sheds-Sheec 4 B. AMES COOKING APPARATUS Filed Nov. 9, 1938 July 1, 1941.

5 Sheets-Sheet 5 M it?! 1/9? 12 0 I 1,37 12% I O 4- U, 1 k 0 1;

I i ismi EU 0 )5 Patented July 1, 1941 UNITED STATES PATENT OFFICE Application November 9, 1938, Serial No. 239,613

8 Claims.

This invention pertains to electrically heated cooking apparatus useful for broiling, baking, roasting, toasting, frying, boiling, and in fact every conceivable kind of cooking, the apparatus being of self-cleaning type and being operative satisfactorily when supplied with direct or alternating current which may be of usual houselighting voltage, the present invention being an improvement upon the apparatus disclosed in my copending application for Letters Patent Serial No. 155,946, filed July 27, 1937.

While my aforesaid application disclosed a highly useful and desirable type of aparatus, it is the general object of the present invention to provide novel features of improvement capable of embodiment in apparatus such as disclosed in my aforesaid application, but providing additional functional advantages.

In accordance with the present invention I provide a very simple form of fume and odoreliminating means including a light, easily lifted valve device, consisting of thin sheet metal, for instance aluminum foil, cooperative with a complemental part to define a narrow corridor through which the gaseous substances are constrained to move on their way to the exit passage. The valve and the part which define such narrow corridor are normally in contact, and as said part is heated very hot by direct radiation from the heat source, the valve is also highly heated. During cooking, the valve separates from said assoc ated part at intervals, in response to pressure differential at its opposite sides, thus providing the narrow and hot-walled corridor in which the gaseous products are broken down and odors eliminated. Preferably a portion at least of the thin sheet material forming the valve means is flexible so that it fits snugly in contact with its complemental part under normal conditions, thus closing the exit passage. When cleaning the apparatus. the valve device remains closed and so substantially prevents any draft through the apparatus. Thus it is possible to obtain and maintain the high internal temperature requisite for cleaning.

Since it is an important feature of the present apparatus that it operate usefully with a minimum current consumption and to this end that it conserve the heat energy supplied as fully as is practically possible, the present invention provides for so supporting and uniting the several parts of the apparatus as to reduce to a minimum the loss of heat by direct conduction from the interior to the exterior of the device.

As some heat necessarily escapes, partly by conduction and partly in the gaseous substances which emerge through the exit passages, it is proposed, in accordance with the present invention, to provide for the useful employment of such escaping heat, for example for heating water, keeping cooked food warm, warming or drying dishes, etc., and to this end the apparatus may have a top or cover which isso shaped and designed as to provide a suitable support for such articles or containers as are to beheated or warmed. If desired the support may take the form of an open rack mounted upon but notconstituting an essential part of the apparatus,

per se.

In the apparatus disclosed in the aforesaid application, provision is made by the use of a covered pot or pots for boiling or otherwise cooking articles. At the inception of boiling orsteaming some considerable time elapses before the liquid in the pot reaches a cooking temperaturethe liquid being heated mainly by conduction through the walls of the pot, and during-this interval, and before the upper part of thepot cover becomes filled with vapor, the upper surfaces of the articles being cooked may become too highly heated by direct radiation from the heat source which pass through the cover and which may dry oreven brown the articles being cooked. Inmy aforesaid application it ls-suggested that a bafile plate be placed in the upper part of the pot cover to avoid this difficulty.

In accordance with the present invention an improved pot cover is provided having hollow walls providing an annular space for the reception of liquid and which acts both as a baffle to cut down direct passage of radiant heat through the pot cover and also as a source of steam which enters down through suitable openings into the upper part of the pot and not only cooks the articles in an atmosphere of hot or even superheated steam, but protects them from the direct impact of energy from the heat source, so that all danger of scorching or undesired browning is avoided.

In the arrangement disclosed inv the aforesaid application the-pot cover is providedwith an opening for the escape of steam, but in the improved construction herein shown the cover has no outlet opening and fits the pot closely enough to prevent the rapid escape of steam, thereby to ensure a vapor pressure within the pot' corresponding to an adequate cooking temperature.

Preferably, though not'necessarily, the heat source is so designed as optionally to emit heat energy at different rates; for example, the heat source may comprise two independent resistance coils, one or both of which may be supplied with current at will, If two coils be employed, one may, for example, be placed in series with an automatic thermostatic control operative to cut off current from said coil when the temperature within the cooking chamber becomes excessive.

As th portable apparatus herein disclosed is of limited capacity it may be desirable to use several such devices at the same time, but if several of these devices are to be used where the supply of current is limited, for example, if intended to be connected to the usual houselighting current, precautions must be taken to avoid overloading the circuit. To this end the current supply means (plug or switch) is preferably so designed that current may be supplied selectively to either or simultaneously to both devices for furnishing either of two stages of heat, that is low or medium, but so that current can be supplied to but one of the devices to furnish the highest stage of heat.

The foregoing, together with other and further objects and advantages of the invention, will be set forth in the following more detailed description and in the accompanying drawings in which Fig. 1 is a side elevation of one embodiment of the invention;

Fig, 1 is a small scale diagrammatic view partly broken away, showing apparatus of different shape;

' Fig. 2 is an end elevation showin the device of Fig. l with the cover fully open;

Fig 3 is a sectional view of the apparatus when arranged for broiling or grilling food;

Fig. 4 is an incomplete sectional view of the apparatus when arranged for steaming or boiling;

Fig. 5 is a fragmentary plan view of the top of the pot cover shown in Fig, 4, with certain parts broken away;

Fig. 6 is a fragmentary section on the line 6-6 of Fig, 5;

Fig. 7 is a diagrammatic plan view to small scale of the apparatus when provided with a rack upon which food may be kept warm or food, dishes, towels or the like may be dried by the heat energy emitted from the apparatus;

Fig. 8 is a diagrammatic side elevational view to small scale of the upper portion of the apparatus shown in Fig, '7;

Fig. 9 illustrates one form of heating element for such apparatus;

Fig. 9 is a plan view illustrating another form of heating element;

Fig. 10 is a diagrammatic view of a battery of two cookers having common control means for the heating elements thereof;

Figs. 11 and 12 illustrate one type of such control means;

Fig. 13 is a diagrammatic view illustrating another form of control means;

Fig. 14 is a small scale diagrammatic front view of another embodiment of the invention;

Fig. 15 is a fragmentary section, to larger scale, on the line l5| 5 of Fig. 14;

Fig. 16 is a diagram of the electric circuits controlling the heating element.

The apparatus forming the present invention has certain general features in common with the apparatus disclosed in the co-pending application.

The illustrated embodiment of the invention is a cooker substantially elliptical in form, although it may be of any desired shape, for example, square or round, and consisting of a base I and cover 2. The base 1 comprises an outer shell 3 and inner shell 4 preferably of sheet metal, suitable insulation 6 in the form of a sheet of polished aluminum or other metal having a hole in the center thereof being interposed between the members 3 and 4. When the insulating plate 6 is employed it may be provided with a down-turned peripheral flange which rests upon the shell 3 and may be secured to the shell 4 by studs, bolts, rivets or the like and separated therefrom by spacers 5. In place of the metal plate 6, plates of other material may be employed for insulation or the air space between the shells may be relied upon for that purpose.

At the center of the shell 3 is provided an upstanding annular boss I, which is open at the top, and which, when the insulating plate 6 is used, serves to support it at the center thereof. The shell4 is provided at its center with a downwardly extending annular boss 8 surrounded by a ring 8 which is fixed to the underside of the shell 4 and extends through the hole in the plate 6 and boss I. An opening or passage is thus provided through the entire thickness of the base for purposes to be described hereinbelow.

The shell 3 includes an upstanding peripheral flange 9, a horizontal outwardly extending rim l0, and a downwardly extending flange II which stiffens the rim l0 and supplies a pleasing finish to the base. Y

The base is supported upon legs l2, each leg having a foot or pad I3 designed to rest upon a suitable support S, such for example as a table top. Each leg preferably extends upwardly in front of the flange l i into contact with the under surface of the rim I0 and downwardly in contact with the flange terminating in an ear or tab [5, which underlies the main part of the shell 3 and may be secured thereto by spot welding or rivets. The base is here shown supported by four legs symmetrically disposed (see Fig. 7). The legs I 2 at each side of the hinges connecting base and cover are offset at [4 to insure steadiness of the cooker when the cover is raised (see Figs. 2 and 7).

The inner shell 4 has an upstanding rim I6 which preferably terminates in a beaded or otherwise finished edge l1.

The cover, as here illustrated, comprises a substantially vertical side wall and a domeshaped top. The side wall preferably includes an inner shell 23 and an outer shell 24 of any suitable material. For example, the shell 23 may be of aluminum or some other non-oxidizing metal having a low heat absorptive capacity, while the outer shell 24 may be of common or stainless steel. The space between the shells 23 and 24 is practically closed at the bottom by an annular plate 25 having a downturned flange which fits between the inner surface of the shell 24 and the upturned lower margin of the latter shell. The plate 25 overlies an outwardly projecting flange 26 formed by the upturned and outwardly extending lower edge of the shell 23 and is connected to the latter by screws 22 passing through spacing washers of insulating material. The space between the shells 23 and 24 is closed at the top by an annular plate 21 having an upturned flange which fits between the inner surface of the shell 24 and the inwardly and downwardly turned upper edge of the latter. The plate 2! extends inwardly over the top of the shell 23. A gasket 28 of asbestos or the like is interposed between the upper edge of the shell 23 and the inner downturned edge of the plate 21. n The inner portion of the latter plate is of channel shape in cross section; asshown at 29, with its inner edge, as stated; resting upon the gasket 28 while an intermediate portion of the plate 21 bears against the free outer edge ofthe gasket and deflects the latter downwardly. The top 30 of the inner shell as here illustrated is domed and has a central. opening therein, i

In addition to the top 30 of the inner shell the top of the cover comprises an intermediate shell 31 and an outer shell 32. The shells 3| and 32 are separated and the space between them is closed by a horizontal flange 33 on the intermediate shell 3!, which bears against and may be welded to an annular bead 34 at the edge of a similar horizontal flange 35 on the outershell 32. The top of the cover is secured to the side wall by a plurality of screws, rivets or the like 36 passed through the flanges 33 and 35 and entering the channel 29 of the plate 21. Spacers 31 held between the flange 33 and the upper edge of the side wall of shell 24 by the screws 36 provide a discontinuous slot 38 extending peripherally around the cover which provides free communication between the outer atmosphere and the space 39 between the shells 30 and 3| The space 40 between the shells 3| and 32 provides air insulation and if desired may contain additional insulation such as polished aluminum foil; rock wool or the like.

Fixed at the top of the cover below the central opening 42 in the top 30 of the inner shell .is a heating element 43. The heating element 43; as shown in Fig. 9, comprises a tubular core 44 of porcelain or other refractory material having bars 45 at each end thereof. Onthe outer surw face of the core are formed two interrelated helical grooves in which are supported coils 41 and 48 laid in the respective grooves. ,The ends of the coils are welded or otherwise fixedly secured to clips 49 and 50 respectively. The clips at one end of the element are integral with a post and each clip at the other end of the element is integral with a post 52. is suspended from the top 30 by the sti'apsBl and 52 which are suitably insulated from the top and are fixed respectively to the end bars .45 of the tubular core. Within. the core may be placed a metal rod or tube 46 for a purpose to be set forth below. .7

In Fig. 9 a modified form of heatingelemen't is illustrated wherein in place of the cylindrical tubular core 44 of refractory material above'described, there is employed an annular ring" 4 of refractory material. This ring is supported by brackets or posts 5 and 52*, corresponding to the posts 5! and 52 above described; and sup ports two resistance coils 41 and 48 respectively; lhese coils are connected to the posts 5!? and 52 in the same way that the coils and 4B are connected to the posts 5! and 52, all as. above described.

1 Mounted upon the cover 2 are prongs 53 (Fig; which are electrically connected tov the posts 5! and 52 by conductor 54. For convenience in description it is assumed that the prong 53 is connected to the post 52 integral with the clip 49 of the coil 41; that the prong 53 is connected to the post 5i integral with the clipsED of both coils 41 and 43; and that the prong 53 is con nected to the post 52 integral with the clip 49 of the coil 58. Obviously by suitably connecting the prongs to a source of electrical current either or both coils will be energized to wit; if con- The heating element .directly upon the support 58,

nected by the prongs 53 and 53? the coil 41 will produce a low heat; if, connected by the prongs 53 and 53 the coil 48 will produce a medium heat; and if connected byall three prongs both coils Will produce a high heat. Qbviously provision for further variations of heat may be provided.

The specific form of cooker herein shown is primarily, designed for use with the ordinary house-lighting current and will operate satisfactorilywitha current consumption of from 00 to 14400 watts. Thus it may be connected to the ordinary service outlet without endangering the insulation usually employed in house wiring circuits so that no special wiring is needed. An automatic cut-out 55 (Fig. 3) mounted within a case 56', secured to the outer shell 24 of the cooker; is preferably connected in series with one of the coils, preferably to the medium heat coil 48.; the parts being so designed, for example, that the current may be cut in half when the heatwithin the cooker reaches a certain temperature.

Mounted in the space 39 between the shells 30 and .3] of the cover top, is an automatic valve device 51 (Fig. 3) whose central and upper portion normally rests upon the upper surface of a support. 58 held in spaced relation to the inner' shell 39. by means of suitable brackets. The valve 51 preferably consists of a piece of very thin and lightsheet material. Preferably the lower or skirt-likeportion 5'! at least of this valve is flexible so that it tends to conform closely to the contour of the outer surface of the innerhmember 3110f the cover top. on which it normally rests. When the valve 51 is in its normal closed position it substantially cuts off communication between the space 42 immediately beneath the support 53 and the space 39 between the members 39 and 3!. As here illustrated. the heating element 43 is directly below the opening 42 and thus some of the rays of radiant energy emitted by the element 43 pass upwardly through the opening 42 and impinge and are transmitted by conduction through the latter to the central part of the valve device 51. Moreover, as the inner member 3!! of the cover top becomes highly heated by. the rays of energy emitted by the heat source 43; and as the skirt portion 51 of the .valve normally rests upon the outer surface of the member 39, the skirt portion of the valve is likewise highly heated by its direct contact with the member 3!]. When this valve is closed;, it practically cuts off communication between the. interior of the cooker (through the opening 42 and space 42 and the space 39 which leads to the outlet passage 38, and during the cleansing of the apparatus after cooking, as will hereinafter be more fully described, this valve remains substantially closed and thus prevents. any draft through the apparatus. In this way the heat energy is conserved so that a very high temperature may be attained. Likewise at tbe beginning of the cooking operation the valve 51 remains closed, and it is thus possible to raise the temperature very rapidly within the apparatus when the current is turned on even when the only current available is that supplied by the usual house-lighting circuit. However, during the cooking operation and as gases and vapors are evolved from the material being cooked, the

' resultant pressure differential at opposite sides of the valve 51 will cause the latter to rise and fall and thus, at intervals, open a narrow corridor between the opposed surfaces of the parts 30 and 57 This corridor leads from the space 42 to the space 39 and through this corridor vapor or gaseous products of cooking may escape to the exit passage 38. As above stated the members 33 and 57 become very hot and as the vapors and gases on their way to the exit opening 38 must pass along the very narrow hot Walled corridor, the complex odor-forming substances are broken down into simpler and odorless compounds before they emerge through the exit passage 38. Since the valve skirt flares downwardly and outwardly and is of constantly increasing diameter toward its outer edge, the peripheral dimensions of this narrow corridor constantly increase, so that the velocity of flow of the gaseous substances decreases as they move toward the exit 38, and ample time is afforded for the odor destroying action to take place.

The cover 2 is preferably connected to the base I by leaf hinges 59 and 88 (Fig. 7) so that it can not be wholly separated therefrom. As a support for the cover while open, there may be provided a bracket 8| of sheet metal, having a foot 62 and a U-shaped bend G3 on which the cover directly rests. The bracket 8| is secured to the base I by means of an upwardly extending tongue 84 which enters a slot formed by a strap 65 carried by the base and is removably secured therein by a set screw 86. In order to avoid direct loss of heat through the bracket 6| when the cover is closed, the bracket may if desired be so formed that normally the foot '62 is raised above the support S. The bracket, however, is so inherently flexible that the weight of the cover 2 will depress the foot 62 into contact with the support S (see Fig. 2). The slots (Fig. 3) in the leaves of the hinges 59 and 68 attached to the base are preferably elongate so that the pivot pins can travel vertically therein as will appear from a comparison of the showing in Fig. 2 with that in Figs. 3 and 4.

The cover is adapted to be opened and closed by a handle 81 (Fig. 2) which includes a shaft 68 pivotally mounted in a bracket 18 carried by the shell 24. Fixed to the shaft at right angles thereto is a tongue H. Should it be desired to support the cover 2 in a partly opened position, the tongue ll after the cover has been raised sufliciently, may be swung inwardly by rotating the shaft 68 so that the tip of the tongue will rest upon the rim Ill when the cover is lowered.

In Fig. l a cooker of different external shape is illustrated, it being understood that this cooker will be constructed in all substantial respects like that above described, except that in this instance the top of the cooker is substantially flat, as indicated at F, thus affording a support for cooking utensils or the like which may be set thereon and which will be warmed or kept warm by heat escaping from the interior of the cooker.

It is obvious, as indicated in Fig. 1 that a plurality of cooking pots P P P etc., each like the pot P hereinafter described, may be placed at the same time within the interior chamber of the cooker, thus providing for the simultaneous cooking of different substances.

When the cooker is used for broiling, grilling, or similarly processing food, a pan I 8 and rack 12 are employed, as shown in Fig. 3. The pan !8 has an outwardly directed marginal portion H! which may rest directly upon the beaded edge 11 of the inner shell 4 of the base, but if deemed necessary it may be so supported as to avoid any loss of heat by conduction to the wall it of the shell 4. As shown, the outer edge of the part I9 is turned up to form a flange IS. The upper face of the pan is downwardly concave and adapted to catch grease and at its center, which is the lowest area of the pan, the pan has an opening 20 and a grease delivering pipe 2|. The pipe is suitably secured to the pan and extends downwardly through the boss 8 and ring 8*- so that the rease is delivered out of the cooker into a receptacle 22. A rack 12 of any desired type, and having legs 14, rests upon the pan [8 and supports the food.

When the cooker is used for steaming, baking, boiling, roasting or otherwise cooking food, the pan l8 and rack 12 are replaced by a covered pot P, here shown as comprising the pot proper, designated 15, which may rest directly upon the inner face of the shell 4 and which may close the opening through the boss 8 (see Fig. 4), and the cover 15. The pot cover comprises a domed inner shell l1 and a domed outer shell 18. The inner shell terminates at the bottom in an outwardly extending horizontal flange l9 and a downwardly directed rolled edge 80. The flange rests on the upper edge of the pct 15 and the downwardly directed edge or rim 88 is of such diameter as to fit quite snugly about the top of the pot. The outer shell 18 is spaced from the inner shell 11 and its bottom edge is clamped in the rolled edge of the inner shell so that the shells are firmly connected in leakproof relation.

In the top of the outer shell is an opening 8! (Fig. 4) which is defined by an upturned flange 82 fixed to or integral with the shell 18. A cap 83 fits down over this flange and normally closes the opening 8!. A strap 84, under which a lifter or other suitable implement may be inserted to facilitate lifting the pot cover 76, may conveniently be attached to the flange 82. In the top of the inner shell ll (Fig. 6) there are provided openings 85, each surrounded by an upstanding flange 85, here shown as integral with the inner member 11 of the pot cover. These flanges are of such height that the upper edges thereof assist in supporting the upper central portion of the shell 18. However, these flanges are notched or otherwise shaped to provide openings 81 giving communication between the space 88 between the inner and outer walls of the pot cover and the space within the flange 86 and which communicate with the interior of the pot.

The food to be cooked is placed in the pct 15, and is preferably supported above the bottom of the pot by means of a suitable rack or the like if it is to be steamed or boiled, although it may, if desired, be placed directly upon the bottom of the pot or in another receptacle resting upon the pot bottom. The space 88 between the walls of the pot cover is then partially filled with water through the opening 8!. The cooker is now closed and heat is supplied. The heat energy from the heat source 43 impinges upon the outer surface of the outer member 18 of the pot cover, and this heat is conducted down to the water in the space 88 and gradually heats this water until vapor is evolved from its upper surface. The vapor given off from the liquid rises and enters through the openings 8'! and thence passes downwardly into the interior of the cooking pot. As the vapor rises between the walls '11 and 18 it becomes highly heated and in fact enters the pot in the form of superheated steam and this steam rapidly heats the contents of the pot. By'the time the water has all boiled out from the space between the walls 11 and 18, sufficient heat is being transmitted by conduction downwardly along the sides of the pot to heat the bottom of the pot and the interior walls of the cooking chamber," so that thereafter the contents of the pot are maintained at the cooking temperature. a

The cooker depends for its operation upon the radiant energy emitted fromthe'heating element 43; The top 30 of the cover which supports the element 43 is, as here shown, arcuate'and preferably parabolically curved so that all rays from the element 43 falling upon the walls are reflected uniformly and directly upon the food when roasting, grilling or the like is going on, or upon the cover of the pot P when that is used. The element 43 is preferably heated toapproximately a cherryred heat, 'for it is foundtha't at'this heat the energy waves emitted therefrom"-penetrate the food more effectively than if thetemperature of the heat source'were raised to a whiter heat.

The walls of the cooker upon which these rays fall are of aluminum or coated withaluminum; or of such other material or so finished as to have a relatively low heat and light-absorptive capacity, whether the rays be o'if'lo'ng' orshort wave length. For instance, stainless steel or the like coated with a vitreous enamel may be useful under certain conditions. The radiant energy is thereby directed substantially without loss upon the food. The valve 51 normally almost completely closes the exit from the chamber within the cooker so that the steam and cooking vapors created therein are held until the differential pressure at the inner and outer sides of the valve causes the latter to open. This introduces a time element with respect to the escape of vapors and gases from the cooking chamber, allowing proper ventilation and even the introduction of fresh air at times. On the other hand, as ab(' vede scribed, the valve device is so devised that any vapors escaping from the cooking chambermust pass in such intimate relation to highlyheated surfaces as to insure elimination of all objectionable odors. Apparently the highly heated opposed surfacesof the closely adjacent parts 30 and 5'! have a certain catalytic effect which contributes to this breakdown of the complex odoriferous substances which are evolved in cooking.

When used for cooking foods by steaming, boiling, roasting or the like, the radiant energy emitted from the heating element 43 falls directly upon the outer walls of the pot P and raises the temperature thereof. The heat thus created in the outer shell I8 of the pot cover. performs two functions, to wit it is transmitted by conduction to the lower portion or pot proper to assist in raising the temperature of the contentsthereof. and it is transmitted as above described to the water in the space between the inner and outer shells of the cover so as gradually to vaporize this water.

As already suggested the vapor rising from the steaming water in the cover is heated as it rises toward the passage 81 and enters the pot above the boiling point. This hot vapor heats the contents of the pot and also maintains a relatively moderate temperature in the upper part of the pot,and while raising the material in the pot to a, cooking temperature, protects it from burning, scorching or undue browning. Duringsuch cookins the vapor evolved from the cooking material may escape slowly through the joint at the juncticn of the pot proper and the cover; thus maintaining suiiicient pressure within thepotto make it possible to cook at a temperature of 21% or more, it being noted that the pot cover fits quite snugly about the upper edge of th lower part 15. V

When roasting in the pot, the food to be roasted is preferably placed upon a rack supporting it slightly above the bottom of the pot. As the roasting operation approaches completion and the bottom of the pot becomes highly heated, the liquids in the bottom of the pot are projected by whatmay be termed explosive action forcibly against the under surface of the food, thus properly basting the latter. Just before the completion of the roasting operation the pot may be opened and the food turned over so that the surface which was previously at the top will be exposed to this basting operation.

After the cooking has been completed the supply of current to the heating element 43' is cut off, the cover 2 is raised, or the door, if one be provided, is opened and the food is removed. The cooker, together with the utensils used, c. g. the pan l8 and rack 12, or the pan l5 and cover 16 can,' if necessary, be cleaned by closing the cover 2 or door and again energizing the heating element 43. The radiant energy emitted from the element acts upon the surfaces of the utensils and the walls of the cooker to raise the temperature thereof and any food or grease thereon is attacked and converted by the rays ofenergy into' vapors. The heat within the cooker consumes such food or grease and breaks up the vapors therefrom so that no odors will be emitted from the cooker.

As pointed out above, the amount of current supplied to the heating element 43 and the amount of radiant energy emitted therefrom may be varied in accordance with the conditions re quired. The refractory core 44 is so designed that it becomes heated to that temperature at which it emits radiant rays of the wave lengths best fitted for cooking and cleansing and forthe burning and destruction of objectionable odors and smoke. The metal terminals and supporting bases are preferably of nickel or other metal coated with a low light-absorptive substance, because it does not tarnish or oxidize in the intense heat and does not absorbto an undue extent the rays of radiant energy falling thereon. A rod 46 of Monel metal, nickel or other metal having slow oxidizing but high absorptive qualities may be inserted within the core 45 should it be desired.

As previously pointed out, the current required may be of three different amounts, to wit, that for the coil 41 alone, that for the coil 48 alone; and that for both coils simultaneously. The amounts required for either coil alone are relatively small and if desired two cookers may be supplied at the same time from the sameline with either of these amounts of current. The amount of current required for both coils simultaneously, however, is so large that to supply two cookers with such an amount at the same time would place an undue load upon the line (Fig. 10).

One means of attaining this result is shown in Figs. 11 and 12 as comprising an outlet box I00 and two plugs lfll each provided with prongs I02, I03 and I34 and connected by a lead [05 v and plug 106 to one ofthe cookers. The outlet 'box I00 is provided with" a plurality of prong receiving cavities connected in any suitable manner with a three wire house line (not shown) through which the usual 119 volt current flows. The cavity IIG is connected to one feed wire, the cavity III to the other feed wire line, the cavities IIE to the common return wire, and the cavities I i3 are electrically dead and serve merely to accommodate and receive aprong under certain conditions.

It will be understood that the prongs of each plug Iiii are connected with the prongs of a cooker by the plug I06. For convenience it is assumed that these conditions are as follows: prong I92 with prong 53 prong I33 with prong 53 and prong I84 with prong 53. Hence when the prongs of the plug ISI of a cooker enter a vertical row of cavities either H0, H2 and H3, or I I I, I I2 and I I3, one of the coils of that cooker is energized. The coil 41 is energized if the prong I32 is in the cavity III and the coil 48 is energized if the prong I54 is in that cavity. As a guide or manual indicator, the opposite sides of the plug may be colored or provided with indicia or may be differently formed. When the prongs of a plug enter the horizontal row of cavities I I0, I I2 and III both coils ll and 48 of the cooker are energized. Attention is called to the fact that while both cookers may be simultaneously at low or medium heat, the connection of either cooker for high heat prevents any connection of the other cooker and thereby overloading of the line is prevented.

In Fig. 13 there is diagrammatically illustrated a switch device which may be used in substitution for the plugs above described. This switch device comprises two rotatable knobs I20 and I2I respectively, each of generally circular contour and having their axes so spaced apart that their curved peripheries are closely adjacent. Each knob has at one point a projecting lug I22, I23 respectively, and at a diametrically opposite point an areuate recess I24, E25, respectively. The switch contacts (not shown) may be of any of the usual types such as are employed for supplying current at different rates to the heating elements of electric ranges or the like. However, the connections are such that when the lugs of the two knobs are oppositely directed no current is supplied to either coil. Each knob may be turned independently of the other through an arc of 90 either right or left, thereby to supply current for low or medium heat respectively. On the other hand only one knob at a time can be turned from the neutral position through 180 so as to direct its lug inwardly and thereby to furnish its respective coil with current for the highest degree of heat, since it is only when one knob is in the on" or neutral position that'the lug of the other knob can enter the recess of the first knob and thus occupy the high heat position.

While as here shown the entire top of the cooker is arranged to be opened so as to give access to its interior, the cooker may be constructed, as diagrammatically indicated in Figs. 14 and 15, to have a top 2 which is normally stationary and to have a hinge door H in its side wall similar to an oven door. This door H is so constructed and arranged as, when closed, to close openings in both the inner and outer shells 23 and 24 it being understood that the inner surface 23 of the door H will be of a non-light-absorbent material or have a nonlight-absorbent surface finish generally similar to that of the inner shell 23 itself.

While one embodiment of this invention has been shown and described it will be understood that the invention is not limited thereto and that other embodiments may be made without departing from the spirit and scope thereof as set forth in the following claims.

I claim:

1. A cooker of the class described having a base and a cover therefor, said base and cover defining a cooking chamber, said cover comprising a side wall and a top, the cover having an exit opening, said top including an inner shell having an aperture therein, and a second shell spaced from the inner shell to provide a passage leading from said aperture to the exit opening, means for heating said chamber, and a valve carried by and cooperating with said inner shell, said valve normally resting upon the inner shell and substantially closing said passage but being arranged to open in response to differential pressure within and without the chamber, thereby to permit the escape of vapor from said chamber through the aperture and passage to the exit opening.

2. A cooker of the class described having a base and a cover therein, the base and cover defining a cooking chamber, the cover comprising a side wall and a top, means providing an exit opening in the cover, said top including an inner shell having an aperture therein, a second shell spaced from the inner shell thereby to provide a passage leading from the aperture to the exit opening, a heating element suspended in the cooking chamber and below the aperture in the inner shell, and a light, easily movable valve element normally substantially closing said passage and thereby restricting the flow of gaseous substances therethrough, the valve normally resting upon a heated portion of said inner shell so as to become highly heated and being constructed and arranged to rise in response to differential pressure within and without the chamber, thereby to afford a narrow passage along the hot wall of the inner shell for the escape of vapor from said chamber, whereby any complex odor-forming substances in the vapor are broken down.

3. A cooker of the class described having a base and a cover therefor, the base and cover defining a cooking chamber, the cover having an exit opening, a heating element within the chamber, the surface of said cover defining the cooking chamber being highly heated by said element and a valve within the cover, the valve being so designed and arranged as to delay the escape of gaseous: substances from the chamber through the exit opening and to keep such gaseous substances in close and intimate contact with such highly heated surface during their passage from the chamber to the exit opening, whereby any complex odor-forming substances in the vapor are broken down.

4. A cooker of the class described comprising outer walls, inner walls spaced from the outer walls and in poor heat-conducting relation to the latter, the inner walls defining a cooking chamber, the inner surfaces of the inner walls being of low heat-absorptive capacity, a source of radiant energy within the chamber, means providing for the escape of liquid from the lower part of the chamber, means providing for the escape of gaseous substances from the upper part of the chamber, and automatic valve means coacting with the outer surfaces of the inner walls normally preventing the escape of such gaseous sub stances.

5. A cooker of the class describedcomprising outer walls, inner walls spaced from the outer walls and in poor heat-conducting relation to the latter, the inner walls defining a cooking chamber, the inner surfaces of the inner walls being of low heat-absorptive capacity, a source of radiant energy Within the chamber, and means providing a, passage of variable capacity for the escape of gaseous substances from the upper part of the chamber, said passage having highly heated Walls operative to break down complex odoriferous substances in escaping through said passage thereby to eliminate objectionable odors evolved in cooking.

6. A cooker of the class described having a base and a cover therefor, said base and cover defining a cooking chamber, a heating element within the chamber, said cover comprising an inner and an outer wall spaced apart, means providing an exit opening in the outer wall leading from the space between such walls, an aperture in the inner wall through which gases may flow from the cooking chamber into the space between the inner and outer Walls, and valve means carried by the inner wall and normally resting thereagainst to prevent the escape of such gases through the exit opening.

I. A cooker of the class described having a base and a cover therefor, said base and cover defining a cooking chamber, a heating element within the chamber, said cover comprising an inner and an outer wall spaced apart, means providing an exit opening in the outer wall leading from the space between such walls, an aperture in the inner wall through which gases may flow from the cooking chamber into the space between the inner and outer walls, a support on the outer sur= face of the inner wall above said aperture, and valve means resting upon said support and upon the outer surface of the inner wall to prevent the escape of such gases through the exit opening until raised out of contact with the inner wall by the pressure differential created by the evolution of such gases in the chamber.

8. A cooker of the class described having a base and a cover therefor, said base and cover defining a cooking chamber, a heating element within the chamber, said cover comprising an inner and an outer wall spaced apart, means providing an exit opening in the outer wall leading from the space between such Walls, an aperture in the inner wall through which gases may flow from the cooking chamber into the space between the inner and outer walls, a support on the outer surface of the inner wall above said aperture, and valve means for controlling the escape of such gases through the exit opening, said valve means resting at its center upon said support and having a flexible skirt-like portion which normally rests upon the outer surface of the'inner wall and is heated by its contact therewith, said portion being raised out of contact with the inner wall by the pressure differential created by the evolution of such gases in the chamber, the heated inner wall and valve skirt acting to break down any complex odor-forming substances in the gases.

BUTLER AMES. 

